Learn Dutch: Ik weet dat u het karton heeft weggebracht. - I know that you have taken the cardboard away.

It comes from the separable verb wegbrengen (to take away). To make the past participle, the -ge- is injected right between the prefix (weg) and the past participle of the base verb (bracht). Because brengen is irregular, its participle is gebracht, giving us weggebracht.

Why are the verbs heeft weggebracht piled up at the end of the sentence?

The word dat (that) introduces a subordinate clause. In Dutch, a subordinate clause pushes all its verbs to the very end of the sentence. The main clause (Ik weet) keeps standard word order.

Can I change the order to weggebracht heeft at the end of the sentence?

Yes, you can! When you have an auxiliary verb (heeft) and a past participle (weggebracht) at the end of a subordinate clause, you can put them in either order. Both heeft weggebracht and weggebracht heeft are perfectly correct.

I learned that 'you have' is jij hebt. Why does this sentence use heeft with the pronoun u?